The present invention, in its several embodiments, relates to receiving and transmitting apparatuses that include microstrip log-periodic antennas and, more particularly, to such apparatuses that include microstrip-slot log-periodic antennas.
The present practicable range of radio frequency (RF) is approximately 10 kHz to 100 GHz, i.e., 0.01 to 100,000 MHz. Within this frequency range electromagnetic radiation may be detected, typically by an antenna, and amplified as an electric current at the wave frequency. When energized via electric current at an RF wave frequency, an antenna may emit in the RF electromagnetic radiation at the RF wave frequency. Log-periodic antennas are typically characterized as having logarithmic-periodic, electrically conducting, elements that may receive and/or transmit communication signals where the relative dimensions of each dipole antenna element and the spacing between elements are logarithmically related to the frequency range over which the antenna operates. Log-periodic dipole antennas may be fabricated using printed circuit boards where the elements of the antenna are fabricated in, conformal to, or on, a surface layer of an insulating substrate. The antenna elements are typically formed on a common plane of a substrate such that the principal beam axis, or direction of travel for the phase centers for increasing frequency of the antenna, is in the same direction. The antenna elements may be placed in electrical communication with an RF receiver and/or an RF transmitter. The analog and digital processing of the detected RF waveform is typically performed by an RF receiver and the analog and digital processing of the transmitted RF waveform is typically performed by an RF transmitter.